U.S. Ranks 131st in Preterm Births

May 2, 2012 -- Preterm birth rates are higher in the United States than in 130 other countries, including many poorer nations, according to a new report from the March of Dimes Foundation, the World Health Organization, and other leading health agencies.

The report, which provides the first-ever estimates of preterm birth rates by country, ranks the U.S. 131st out of 184 countries -- ranking between the Congo and Nigeria -- with a preterm birth rate of 12.0 per 100 live births. Each year in the U.S., nearly half a million babies are born before 37 weeks' gestation.

The March of Dimes has set a U.S. goal of a 9.6% preterm birth rate by 2020.

Worldwide, more than 1 in 10 -- 15 million -- babies are born prematurely each year, and more than 1 million die from preterm complications.

That makes preterm birth the leading cause of newborn death worldwide, and the second-leading cause of death after pneumonia for children under 5, says Chris Howson, PhD, vice present for global programs at the March of Dimes and an author of the report. Those who do survive often face the risk of lifelong health problems.

Of the 65 countries with reliable trend data, all but three show an increase in preterm birth rates over the past 20 years, the report says. The U.S. rate rose to a peak of 12.8% in 2006, after which it started to drop.

Behind the U.S. Ranking

Asked why the U.S. ranked so poorly, Howson cites obesity, which increases the risk of gestational diabetes and high blood pressure; increasing numbers of uninsured women; and the rising rate of elective C-sections, some of which may be scheduled too early.

An increase in the number of older women having babies and increased use of fertility drugs, which increases the chance of multiple births, also play a role, he tells WebMD.

In developing countries, high rates of infections (such as HIV), chronic diseases, and smoking contribute to premature births, Howson says.

The report notes that three-fourths of deaths from preterm births could be avoided if currently available interventions were widely implemented. Most importantly, all women of childbearing age should have access to health care -- before, between, and during pregnancy, Howson says.

Other findings:

More than 60% of preterm births occur in Africa and South Asia.

In the poorest countries, 12% of babies are born prematurely, compared with 9% in high-income countries.

The report also found a dramatic survival gap for preterm babies depending on where they are born. For example, more than 90% of extremely preterm babies born before 28 weeks in low-income countries die within the first few days of life, compared with less than 10% of their counterparts in high-income countries.